Collin McKinney (April 17, 1766 – September 9, 1861) was a land surveyor, merchant, politician, and lay preacher. He is best known as an important figure in the Texas Revolution, as one of the five individuals who drafted the Texas Declaration of Independence and the oldest person to sign it.

McKinney married twice in his lifetime, first to Annie (Amy) Moore on Feb 10, 1794 with whom he had four children (James, Ashley, Polly, and Emeline) before her death in 1804 and then again in 1805 to Elizabeth Leek, with whom he had seven more children (William C, twins Amy and Margaret, Anna C, Samuel L, Eliza S and Younger S).

In 1836, McKinney was one of five delegates from the Red River Colony to the Convention of 1836 which called for Texas to declare its independence from Mexico. He was one of five appointed to draft the Texas Declaration of Independence, and at age 70 he was the oldest to sign it. He would later be a member of the committee that drafted the Constitution of the Republic of Texas and would also serve as a delegate from Red River District and County, Texas to the First, Second, and Fourth Congresses of the Republic of Texas.

In 1846 at age 80 he would move one last time, as a result of one of the worst known floods on the Red River, to the northern portion of the rich blackland prairie of Collin County, Texas to be near several of his children. Although it would be several years before the exact boundary line between Collin and Grayson Counties would be surveyed and clearly identified. He lived just a few miles southeast Liberty, Texas, which was soon renamed Mantua by Younger Scott McKinney who was the founder.

Both Collin County and McKinney, Texas, its county seat, were named in his honor by the Texas Legislature.

McKinney is credited with suggesting to the Texas Legislature that, as new counties were later created in North and West Texas, the boundaries should be about 30 miles square. This would allow a rider to travel to the county seat, conduct necessary business, and return home, all in one day.

Collin McKinney died at his home in Collin County on September 9, 1861 and was buried in the nearby Van Alstyne, Texas Cemetery in the McKinney family plot which was originally the homeplace of Younger Scott McKinney. A historical marker erected by the Texas Historical Commission honors this Texan who lived for over 95 years under the flags of seven different nations.